****Help with making an android app****

[Psynapse_231]

I am making a speedometer app which shows the device speed from getSpeed(). But I keep getting the location as null. I have added the permissions in the manifest file:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>

And, checking the location permissions returns that the loction is available:

LocationManager lm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != 
        PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 
        Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            TextView loc =(TextView) findViewById(R.id.textView3);
                    loc.setText("LocationUnvailable");
            Toast.makeText(MainActivity.this, "First enable LOCATION ACCESS in settings.", 
        Toast.LENGTH_LONG).show();
        } else {
            TextView loc =(TextView) findViewById(R.id.textView3);
            loc.setText("LocationAvailable");
        }
         lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
         this.onLocationChanged(null);

But the element that is supposed to show me the speed of the device shows that the location is null:

public void onLocationChanged(Location location) {
    if (location==null){
        // if you can't get speed because reasons :)
        TextView spd = (TextView) findViewById(R.id.textView);
                spd.setText("Location is null");
    }
    else{
        //int speed=(int) ((location.getSpeed()) is the standard which returns meters per second. In 
this example i converted it to kilometers per hour

        int speed=(int) ((location.getSpeed()*3600)/1000);
        TextView spd = (TextView) findViewById(R.id.textView);
        spd.setText(speed+" km/h");
    }
}

How do I fix this problem? Is there any more permissions I must add? If above snippets dont have enough information, see the full code below:

package com.example.prototype22;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import android.Manifest;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

public class MainActivity extends AppCompatActivity implements LocationListener {

@SuppressLint("SetTextI18n")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    LocationManager lm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            TextView loc =(TextView) findViewById(R.id.textView3);
                    loc.setText("LocationUnvailable");
            Toast.makeText(MainActivity.this, "First enable LOCATION ACCESS in settings.", 
Toast.LENGTH_LONG).show();
        } else {
            TextView loc =(TextView) findViewById(R.id.textView3);
            loc.setText("LocationAvailable");
        }
    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
    this.onLocationChanged(null);

}

@SuppressLint("SetTextI18n")
@Override
public void onLocationChanged(Location location) {
    if (location==null){
        // if you can't get speed because reasons :)
        TextView spd = (TextView) findViewById(R.id.textView);
                spd.setText("Location is null");
    }
    else{
        //int speed=(int) ((location.getSpeed()) is the standard which returns meters per second. In this example i converted it to kilometers per hour

        int speed=(int) ((location.getSpeed()*3600)/1000);
        TextView spd = (TextView) findViewById(R.id.textView);
        spd.setText(speed+" km/h");
    }
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}

@Override
public void onPointerCaptureChanged(boolean hasCapture) {

}
}

Help would be really appreciated :)

[Kilrah]

Do you actually have good GPS reception?

[lal12]

You could try it in the Android emulator, where you can set arbitrary GPS inputs, there you could determine whether it is a problem on your app or your GPS reception. Or use a Fake Location app, which can help debug things like that.

[Psynapse_231]

Omg I totally forgot that I had posted here, I am so sorry, I'll just reply and end this thread. I solved this, i'll discuss the solution too.

On 4/2/2020 at 4:14 PM, Kilrah said:

Do you actually have good GPS reception?

Yes I do get good reception, google maps uses the same basic API and it gives location in seconds

On 4/5/2020 at 5:43 AM, lal12 said:

You could try it in the Android emulator, where you can set arbitrary GPS inputs, there you could determine whether it is a problem on your app or your GPS reception. Or use a Fake Location app, which can help debug things like that.

I tried that, but didn't work. The issue was that I wasn't calling the location as an open method, so it would get location and speed data only when the method was called. I used the functions on application level method, and it worked just fine.